[PATCH 040/109] kernel: add do_getpgid() helper; remove internal call to sys_getpgid()

[Dominik Brodowski]

Using the do_getpgid() helper removes an in-kernel call to the
sys_getpgid() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@xxxxxxxxxxxxxxxxxxxxxxxxxx

Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
---
 kernel/sys.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index f2289de20e19..ebb138b841c8 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1027,7 +1027,7 @@ SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
 	return err;
 }
 
-SYSCALL_DEFINE1(getpgid, pid_t, pid)
+static int do_getpgid(pid_t pid)
 {
 	struct task_struct *p;
 	struct pid *grp;
@@ -1055,11 +1055,16 @@ SYSCALL_DEFINE1(getpgid, pid_t, pid)
 	return retval;
 }
 
+SYSCALL_DEFINE1(getpgid, pid_t, pid)
+{
+	return do_getpgid(pid);
+}
+
 #ifdef __ARCH_WANT_SYS_GETPGRP
 
 SYSCALL_DEFINE0(getpgrp)
 {
-	return sys_getpgid(0);
+	return do_getpgid(0);
 }
 
 #endif
-- 
2.16.3